Power unit



March 5, 1940. R. F. BEAN POWER UNIT Original Filed Sap}. 28, 1937 3Sheets-Sheet 1 lnventofi: Roberft T? Bean, y MMAM His Attorney.

March 5, 1940. R. F. BEAN 2,192,845

POWER UNI T Original'Filed Sept. 28, 1937 3 Sheets-Sheet 2 Fig 7.

Inventor: Robert F Bean,

His Attorneg.

R. F. BEAN POWER UNIT March 5, 1940.

Original Filed Sept. 28, 1937 3 Sheets-Sheet 5 Invenbor: Robert, F Bean,

His Attorney.

Patented Mar. 5, 1940 UNITED STATES PATENT OFFICE POWER. UNIT New YorkOriginal application September 28, 1937, Serial 166,063. Divided andthis application September 9, 1938, Serial No. 229,109

Claims.

This invention relates to power units, more particularly to portableelectrically driven power units for use in food mixing devices and thelike, and it has for its object the provision of an improved device ofthis character.

This invention contemplates the provision of a power unit which is verylight in weight so that it can be manually supported with little effortfor mixing and whipping operations in utensils that 10 are removed fromthe mixing device, such as utensils on a hotplate or a range. It furthercontemplates improved means for attaching an auxiliary appliance to thepower unit.

This application is a division of my copending 18 application, SerialNo. 166,063, filed Sept. 28, 1937.

For a more complete understanding of this invention, reference should behad to the accompanying drawings in which Fig. 1 is a side elevation ofa food mixing device provided with a power unit arranged in accordancewith this invention; Fig. 2 is an enlarged expanded perspective viewillustrating certain elements of the power unit arranged in accordancewith this invention; Fig. 3 is a view similar to Fig. 2, butillustrating certain other elements of the power unit arranged inaccordance with this invention; Fig. 4 is an enlarged elevation chieflyin section of the power unit arranged in accordance with this invention;Fig. 5 is a sectional view taken through the line 5-5 of Fig. 4 andlooking in the direction of the arrows; Fig. 6 is a bottom plan view ofthe power unit of Fig. 4 with parts broken away so as to illustratecertain details of construction; Fig. 7 is a fragmentary front elevationof the power unit of Fig. 6 with parts broken away and parts shown insection so as to.

and looking in the direction of the arrows; Fig.

10 is a view in side elevation illustrating the power unit mounted on asupporting standard in a working position to operate a gear reductionmechanism all arranged in accordance with this invention; Fig. 11 is anenlarged fragmentary view similar to Fig. 10, having parts shown insection so as to illustrate certain details of con-. struction; Fig. 12is an enlarged fragmentary central sectional view illustrating the gearreduction mechanism and its relation to the power unit and also itsrelation to an auxiliary device 1 which it operates, such as a meatgrinder; Fig.

13 is a top plan view of the'organization shown in Figs. 10 and 11, apart of the gear reduction unit being removed so as to illustratecertain details of construction; and Fig. 14 is a fragmentary elevationalong the line I4--l4 of Fig. 11 and looking in the direction indicatedby the arrows. Referring to the drawings, this invention has been shownin one form as applied to an electrically driven power unit particularlyapplicable for use in a food-working device, such as described andclaimed in my above-mentioned copending application. This food-workingdevice comprises a. power unit Ill arranged in accordance with thisinvention, mounted upon a suitable supporting base or standard H. Thepower unit is arranged to drive three beater elements 12 which areintended to operate in small and large mixing bowls l3 and M. The mixingbowls are used one at a time and each is arranged to be mounted upon asuitable turntable ii that is rotatably mounted on the base II. When thesmall bowl i3 is used only the two outside beater elements i2 areemployed, whereas when the large bowl I4 is used all three beaterelements are used in the manner described and claimed in my copendingapplication referred to above. The power unit In is arranged to besupported on the standard II in each of two positions in- .verted withrelation to each other. In the first position (Figs. 1 and 4), the powerunit overhangs the base II and is used for operating the beater elementsl2 for mixing, whipping, and. like food-working operations, and in thesecond inverted position (Figs. 10-13), it operates certain auxiliaryappliances such as a suitable gear reduction mechanism I 6. A suitablehinge section I! is provided between the power unit l0 and the standardI I so that it may be tilted from its position of Fig. 1 to anon-working position in which the beater elements l2 are elevated fromthe mixingbowl. This specific hinge structure is described and claimedin my copending application, Serial No. 228,971, filed September 8,1938. The power unit I0 comprises a'universal series motor I8 having afield winding I81: and an armature winding l9 rotatable within the fieldwinding. Variations in speed are effected by changing the neutralposition of the commutating brushes (not shown) with relation to thefield poles. The rotatable armaturemember is provided with shafts 2| and22 on opposite sides. End cap members 23 and 24 are provided withhearing journals 25 and 26 which journal the shafts 2| and 22respectively. These end members 23 and 24 are of very light-weightconstruction consistent with 5 material mechanical strength. Preferably,they will be made as die castings formed of a relatively light strongalloy, such as die-cast aluminum. To increase the lightness ofconstruction, the end members 23 and 24 are secured together and inspaced apart relation by relatively small inwardly projecting elongatedfingers 21 and 28 formed on the end members 23 and 24 respectively.These fingers, as shown, are formed in pairs opposite each other andopposite the corresponding fingers of the other end members.

The ends of the fingers 21 and 28 abut eachother, and as shown, the endsof the members 21 are provided with inner flanges 29 which interlockwith outer flanges 36 on the fingers 28. The interlocking between thesemembers is more clearly shown in Fig. 4. The end members 23 and 24 havein general a circular form, and the fingers 21 and 28 will be formed onarcs of circles having the same .center as the circles of the endmembers. The end members are prevented from turning relative to eachother by a lug 30a that is received in recesses 30b in the fingers 21and 28.

The end members 23 and 24 are secured together by a single pair ofelongated rods 3| positioned opposite each other and opposite thefingers 21 and 28, as clearly shown in Fig. 4. These rods 3| at theirlower ends are threaded in bosses 32 (Figs. 2, 4 and 8) provided forthem in the lower end member 24 and are directed through aperturesprovided for them in the upper end member, as shown in Fig. 4. On theupper ends of the rods are threaded retaining nuts 33.

The fingers 28 of the lower end member have arcuate seats 34 whichfunction to support the field winding frame 26. The field frame isrigidly secured on these seats by means of steel clamping members 35which are secured to the rods 3| by means of nuts 36 on the rods andover the clamping members, as shown.

The motor shaft 22, as shown, extends through the lower end member 24 tothe other side of this member, and on this other side is a gear train 31which functions to drive a plurality of food-working shafts or spindles38 which function to drive the beater elements |2. As shown, threeshafts 38 are provided, one for each of the beater elements l2.Cooperating with the end member 24 is a gear cap member 39 which is sorelated to the end member 24 that it defines a gear housing 40 for thegear train, and it also cooperates with the end member 24 to support theshafts 38. For this purpose, the end member and gear cap have alinedbearings 4| and 42 which journal the shafts 38. Mounted on and securedto each shaft 38 is a driving gear-43.

The gear 43 on the central driving shaft 38 is relatively thicker thanthe other two and functions to drive them. This central gear 43 in turnis driven by means of a small gear 44 which is rotatably mounted on afixed shaft 45. The small gear 44 is secured to a gear 46. The gear 46is connected with a gear thread 41 formed directly on the end of themotor shaft 22 that projects into the gear housing 40. Thus, the motorshaft 22 drives the gear 46 and this gear in its turn drives the centralgear 43 that drives the two other outer gears 43. Therefore, when themotor is operating all three shafts 38 are operated at the same speed,the two outer shafts operating in the same direction while the centralshaft rotates in a direction opposite to the other two. As shown, thebearings 4| and 42 cooperate with the associated gears 43 to limit thevertical movement of the gears in the gear housing.

The gear cap 39 is secured directly to the end member 24 by means offour screws 50 which pass down through bosses or enlargements 5| in theend member 24 and which are received in threaded engagement in bosses 52in the gear cap member 39.

These same screws 50 also function to secure the shroud ring 53 of thefan 54 that is mounted in a fan chamber 55 between the armature andfield windings of the motor and the lower cap member 24. As shown, thisshroud ring is seated upon the tops of the abutments 5| and it isprovided with apertures 53a through which the screws 50 pass so that itis rigidly secured to these abutments by the. screws. At the oppositeside, the shroud ring 53 is provided with cut-away sections 56 tointerlock the ring with the fingers 26, and moreover, it is providedwith a second set of cut-away sections 51 which interlock with the rods3|. The function of the interlock is to constrict air flow of the fan atthe outside edges of the shroud preventing recirculation of the airwithin the fan chamber 55. The fan 54 further comprises an impeller 58mounted directly on the motor shaft 22 within the shroud ring, as shown.

The spacebetween the cap members 23 and 24 is enclosed by a relativelylight weight sheet metal shell 59 which is folded around the fingers 21and 28 so that its two edges 590. are brought relatively close together,at the front of the power unit. The upper and lower edges 59b of themember 59 are provided with notches 59c relatively close to the endedges 59a, as shown, and these notches are received in pairs of spacedlugs 68 and 6| provided on the end members 23 and 24 respectively. Themember 59 is folded about the end members and fingers and then thenotches 590 are snapped over the lugs 66 and 6| so as to preventseparation of the edges 59a. The seam of the edges 59a is covered bymeans of a band or strap 62 of generally L-shape; the short arm 62a ofthis band is directed over the upper cap member 23 and is secured at therear to the rod 3| in a manner to be presently described. The long leg62b of the L is directed down over the front seam and thence is turnedbackwardly under the bottom of the gear cap member 39 where it issecured to it by a screw 63. As shown, this section of the band isprovided with a reentrant part 620 which is received in an apertureprovided for it in the cap member 39. The screw head 63 functions tohold the reentrant part securely in this aperture. The band throughoutthe length of its two legs 62a and 62b is provided at the edges withinturned flanges 62d, those on the legs 62b engaging the two endportions of the member 59 to prevent springing out of these members, andthose on the legs 62a being received in a recess 64 provided for them inthe upper cap member. The upper and lower edges 59?; of the member 59are received in seats 65 provided for them in the two end members 23 and24 respectively. Preferably a pair of screws 65a will be threaded intothe fingers 21 and 28 so that their heads clamp the edges 59a of thesleeve 59 to the fingers as shown in Fig. 4.

A series of apertures .66 are provided in the lower part of the casingmember 59 and a series of apertures 61 (Fig. 2) are provided through theupper cap member to provide for circulation of air through the chamberin which the motor is located.

The power unit is completed by means of a handle 88 which is secured tothe top member 2'3 through the rear rod 3|. As shown, this handle memberis provided with a portion which overhangs the top of the member 23 andthis portion is secured directly to the rod 3| by means of a nut 88adirected through an aperture provided for it in the handle and receivedin threaded engagement with the upper end of the rod 3|. The nut 88aalso is directed through an aperture provided for it in the upper end ofthe band section 82a, and hence, the nut constitutes a common means forsecuring both the upper end of the handle 88 and the upper end of theband 82 to the power unit. The lower end of the handle is secured to thelower member 28 by means of a screw 88!). As shown, this lower capmember 24 is provided with a rearwardly projecting portion to whichthehandle is secured, and which is also that part of the power unitwhich is hinged to the standard ll.

When it be desired to operate an auxiliary appliance, such as a meatgrinder 89 (Fig. 12), the power unit I8 is removed from the standard andis replaced thereon in an inverted position as shown in Figs. 10 and 11.When in this position,

it is clear that the driving shafts 38 are accessible from the top ofthe power unit. Preferably, the central shaft is used to drive theauxiliary appliances. When the power unit 18 is utilized to drive anappliance requiring a considerable amount of power, such as a meatgrinder, the auxiliary gear reduction unit I8 is used. This gearreduction unit is provided with a housing 18 which has a rearwardlyextending member 18a which is provided with a split section H at itslower end. This split section is fitted over panel members 12 providedon the normal under surface of the power unit l8. And the split sectionIf is se- R cured on these panels by means of a clamping screw '13 whichdraws the split section together tightly on the panels 12. The housing18 at its forward end is provided with a pair of spaced apart dependingpins 18 positioned opposite the central driving shaft 38, as clearlyshown in Figs. 12 and 13. These members at their lower ends have reducedsections that are received in sockets 15 provided in the power unit Ill.The rigidity of the pins H is such that the downwardly extending memberWe may be omitted from the gear reduction unit if desired withoutseriously affecting the stability or operation of the gear reductionunit.

Mounted within the gear housing 18 is a vertical drive shaft 18 which atits lower end is provided with a tongue I1 which is arranged to beinserted in driving slots 18 in the central drive shaft 38. This effectsa driving connection between the shait 38 and the drive shaft 16. Thevertical shaft '16 has a spiral worm 19 which drives a gear 88. Thisgear in turn drives a spur gear 8|. This gear meshes with a gear 82which is mounted on a shaft 83 arranged generally at right angles to thedriving shaft '16. The shaft 83 is not rotary, but is a fixed shaft andthe gear 82 is freely rotatable on it. The gear 82 is provided on itsouter face with a driving tooth 84 which is arranged to be received in aslot 85 provided for it in the driving shaft 86 of the meat grinder Bil.The gear 82 may be moved inwardly axially of the shaft 83 against thebias of a compression spring 81 so that if the shaft 86 be applied tothe reduction unit in any but the proper angular position and its tooth84 is not received in the slot 85, the gear 82 will be pushed backagainst the bias of the spring 81, and when the power unit subsequentlyoperates the tooth into the correct angular relation with reference tothe slot 85, the spring 81 will move the gear 82 to its proper operatingposition shown in Fig-12. The reduction housing I8 has a tapered socket88 which receives a tapered section 89 of the meat grinder 89. The meatgrinder is locked in this socket by means of a pin 88 carried by thegear reduction unit and arranged to be received in an aperture 8|provided for it in the meat grinder, as clearly shown in Fig. 12. Thepin is normally biased to its locking position by means of a compressionspring 82.

The central driving shaft 38 which drives the auxiliary appliancepreferably will be provided with a thrust disk bearing 84 (Fig. 4) totake the and thrust on the shaft. As shown, this disk is mounted in thebearing section 4| for the central shaft 38 that is provided in the endcap member While I have shown a particular embodiment of my invention,it will be understood, of course, that I do not wish to be limitedthereto since many modifications may be made, and I, therefore,contemplate by the appended claims to cover any such modifications asfall within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. In a food-working device and the like, a lightweight portable powerunit comprising opposed end cap members having a pluralityof spacedmating inwardly extending members engaging each other at their ends tospace the cap members apart, means securing said cap members together insaid spaced apart relation, 9. motor unit mounted between said capmembers and having bearings for its rotor mounted in them, the shaft ofthe motor extending through one of said cap members, a gear housingmember into which said shaft extends, gear reduction mechanism in saidhousing member, beater shafts driven from said reduction mechanism, anda light sheet metal shell folded about said inwardly extending membersto enclose the space between said cap members and having its two endedges adjacent each other and interlocked with said cap members.

2; In a food-working device and the like, a lightweight power unitcomprising a pair of cap members, each having a pair of oppositelypositioned spacing members directed toward those of the other cap memberand engaging them so as to space said cap members apart, a thin sheetmetal member surrounding said spacing members and having its end edgesadjacent each other at one side of the unit, the end portions of themember having notches that are received in lugs on the cap members tohold the ends together, a clamping band covering the seam of the two endedges, means securing the band in its position over the seam, a motorhoused within said shell, and beater driving shafts driven by saidmotor.

3.. In a food-working device, a lightweight power unit comprising a pairof spaced end members joined by relatively small inwardly projectingarms, a motor in the space between said end members, a relatively thinsheet metal shell closing said space having its end edges brought closeto each other, the shell having notches adjacent said edges and receivedin lugs provided in said end members to prevent separation of the edges,a band covering the seam of. said edges and preventing outward movementthereof from the lugs, means securing said band in its position oversaid seam, and a beater shaft driven by said motor.

4. In a food-working device and the like, a lightweight power unitcomprising a pair of die castings defining end members having spacingfingers directed toward each other and interlocking each other at theirends, elongated screws holding said end members together, the fingers inone end member having seats, a motor having a field frame resting onsaid seats and secured to said screws to prevent movement thereof fromthe seats, and the motor also having an armature the shaft of which isreceived in bearings in said end members and the shaft projectingthrough one of them, a cap cooperating with said latter end member todefine a gear chamber, reduction gearing in said chamber connected withsaid shaft, beating shafts driven from said gearing, and a lightweightshell surrounding said fingers and enclosing said motor field andarmature.

5. In a food-working device and the like, a power unit comprising upperand lower end members, each having a pair of fingers directed towardthose of the other and interlocking at their ends, elongated screwssecuring said ends together threaded at their lower ends in the lowerendmember, seats on the fingers of the lower end member, a motor having itsfield frame resting on said seats, clamps on said screws holding saidfield frame onto saidseats, the motor also having an armature, bearingsin said end member supporting said armature, a cap member below thelower end member cooperating with it to define a gear housing, gearingin said housing driven by said motor, beater shafts driven by saidgearing, a fan chamber between said motor and lower end member, a fan insaid chamber having an impeller and a shroud around it, the lower endmember having seats in which said shroud rests and common fasteningmeans securing said shroud, lower end member and cap member together.

6. In a food-working device and the like, a power unit comprising adriving motor, end members for said motor, the motor shaft passingthrough one of said end members to the other side, gearing on said otherside, a gear cap member cooperating with said one end member to housethe gearing, beater shafts mounted in said end and cap members, a fanchamber directly above said one end member, an impeller in said chamber,a shroud for said impeller in said chamber, seats on said one end memberreceiving said shroud and common fastening means securing said endmember, shroud and gear cap together.

7. In a food-working device and the like, a

power unit comprising a motor having a field winding and a rotatablearmature, end members having bearings supporting said armature forrotation, the armature shaft projecting through one of said end membersto the other side, gearing on said other side, a gear cap cooperatingwith "said one end member to define a housing for said gearing, beatershafts driven by said gearing, a plurality of elongated rods securingsaid end members together, a fan impeller between said end member andsaid field windings and, armature driven by said motor, a shroud forsaid fan, means on said one end member supporting said shroud, commonfastening means securing said one end member, shroud and gear cap membertogether, and said shroud being interlocked with said rods.

8. In a food-working device and the like, a lightweight portable powerunit comprising a motor, end members having bearings supporting therotor of said motor, the end members having spaced fingers directedtoward each other and engaging each other to space the end membersapart, means securing said end members together, a sheet folded aroundsaid fingers to enclose the space between said end members, and havingits end edges close to each other, means for holding said edges againstseparation, a seal ing strip over the seam of said edges, a handle forsaid power unit, a common fastening device securing one end of each ofsaid strip and handle to said unit, and means securing the other twoends of said strip and handle to said unit.

9. In a food-working device and the like, a lightweight portable powerunit comprising end members having spaced fingers directed toward eachother and interlocked at the ends, a plurality of elongated rods passingbetween said end -members and securing them together, a motor mountedbetween said end members, food-working shafts driven by said motor, athin sheet folded around said fingers to enclose the space between saidend members and having its end edges adjacent each other, meanspreventing separation of said edges, a band sealing the seam of saidedges having one end secured to one end of said unit and its other enddirected back over the end member at the opposite end, a handle directedbetween said end members, common fastening means securing one end ofsaid handle and said other end of aid band to one of said rods, andmeans securing the other end of said handle to said unit.

10. In a food-working device and the like, a lightweight portable powerunit comprising a motor having a rotor, spaced-apart end members havingbearings supporting said rotor and having relatively small spacingfingers that space the end members apart, a sheet folded around *saidfingers to enclose the space between said end members and having its endedges close to each other, means for holding said edges againstseparation, a sealing strip covering the seam of said edges, and meanssecuring the ends of said strip to said end members.

ROBERT F. BEAN.

